Fix Toast timing and alert once per shown Toast

- ToastQueue compared times unsigned: a Toast stamped a few ms after the
  main loop read the clock looked expired, so Toasts were skipped or
  shown late and bursts chained wrongly
- Notifier now beeps and flashes when each Toast appears instead of when
  the Notification arrives, so a burst alerts once per Toast

Co-Authored-By: Claude Opus 5.5 <noreply@anthropic.com>
Claude-Session: https://claude.ai/code/session_01EhqxQ49eCju4CzKYNjZzwT

lib/ui/src/toast_queue.cpp

@@ -9,7 +9,7 @@ void ToastQueue::push(const std::string& text, NotificationLevel level, uint32_t
         queue_.erase(queue_.begin() + (showing_ && queue_.size() > 1 ? 1 : 0));
         if (!showing_) changed_ = true;
     }
-    queue_.push_back({text, level});
+    queue_.push_back({text, level, nextId_++});
     if (!showing_) {
         showing_ = true;
         shownAtMs_ = nowMs;
@@ -19,7 +19,9 @@ void ToastQueue::push(const std::string& text, NotificationLevel level, uint32_t
 
 const Toast* ToastQueue::current(uint32_t nowMs) {
     if (!showing_) return nullptr;
-    if (nowMs - shownAtMs_ >= durationMs_) dismiss(shownAtMs_ + durationMs_);
+    // Signed: a caller's clock reading may be a few ms older than the Toast's stamp.
+    int32_t elapsed = static_cast<int32_t>(nowMs - shownAtMs_);
+    if (elapsed >= static_cast<int32_t>(durationMs_)) dismiss(shownAtMs_ + durationMs_);
     return showing_ ? &queue_.front() : nullptr;
 }
 

lib/ui/src/toast_queue.h

@@ -11,6 +11,7 @@ namespace roro {
 struct Toast {
     std::string text;
     NotificationLevel level;
+    uint32_t id;  // unique per push, to tell two identical Toasts apart
 };
 
 // Notifications waiting to be shown as Toasts, one at a time, each for the same duration.
@@ -34,6 +35,7 @@ class ToastQueue {
     bool showing_ = false;
     uint32_t shownAtMs_ = 0;
     bool changed_ = false;
+    uint32_t nextId_ = 1;
 };
 
 }  // namespace roro

src/ui/notifier.cpp

@@ -9,14 +9,12 @@ constexpr int kLedPin = 21;  // WS2812, powered with the backlight rail (G38)
 }
 
 Notifier::Notifier(EventBus& bus, const Settings& settings) : settings_(settings) {
-    bus.subscribe(EventType::Notification, [this](const Event& e) { present(e); });
+    bus.subscribe(EventType::Notification, [this](const Event& e) {
+        toasts_.push(e.text, static_cast<NotificationLevel>(e.a), millis());
+    });
 }
 
-void Notifier::present(const Event& e) {
-    auto level = static_cast<NotificationLevel>(e.a);
-    uint32_t now = millis();
-    toasts_.push(e.text, level, now);
-
+void Notifier::alert(NotificationLevel level, uint32_t nowMs) {
     if (!settings_.getBool(Setting::Sound)) return;
     M5Cardputer.Speaker.tone(level == NotificationLevel::Warning ? 880 : 1760, 60);
     switch (level) {
@@ -25,10 +23,15 @@ void Notifier::present(const Event& e) {
         default: rgbLedWrite(kLedPin, 0, 16, 40); break;
     }
     ledOn_ = true;
-    ledOffAtMs_ = now + 150;
+    ledOffAtMs_ = nowMs + 150;
 }
 
 void Notifier::update(uint32_t nowMs) {
+    const Toast* shown = toasts_.current(nowMs);
+    if (shown && shown->id != alertedId_) {
+        alertedId_ = shown->id;
+        alert(shown->level, nowMs);
+    }
     if (ledOn_ && static_cast<int32_t>(nowMs - ledOffAtMs_) >= 0) {
         rgbLedWrite(kLedPin, 0, 0, 0);
         ledOn_ = false;

src/ui/notifier.h

@@ -6,20 +6,22 @@
 
 namespace roro {
 
-// Presents Notifications: a Toast, plus a short beep and LED flash (when Sound is on).
+// Presents Notifications as Toasts. Each Toast gets a short beep and LED flash (when Sound is on)
+// as it appears, so a burst of Notifications alerts once per Toast, not all at once.
 class Notifier {
    public:
     Notifier(EventBus& bus, const Settings& settings);
-    void update(uint32_t nowMs);  // turns the LED off after the flash
+    void update(uint32_t nowMs);  // alerts for a newly shown Toast, ends the LED flash
     ToastQueue& toasts() { return toasts_; }
 
    private:
-    void present(const Event& e);
+    void alert(NotificationLevel level, uint32_t nowMs);
 
     const Settings& settings_;
     ToastQueue toasts_{3000};
     uint32_t ledOffAtMs_ = 0;
     bool ledOn_ = false;
+    uint32_t alertedId_ = 0;
 };
 
 }  // namespace roro

test/test_toast_queue/test_toast_queue.cpp

@@ -1,5 +1,7 @@
 #include <unity.h>
 
+#include <string>
+
 #include "toast_queue.h"
 
 using namespace roro;
@@ -64,6 +66,32 @@ void test_reports_when_a_new_toast_appears() {
     TEST_ASSERT_TRUE(q.takeChanged());
 }
 
+void test_asking_with_a_slightly_older_time_does_not_expire_the_toast() {
+    // The main loop reads the time once, then a Notification pushed later in the same pass is
+    // stamped a few ms after it.
+    ToastQueue q(3000);
+    q.push("late", NotificationLevel::Info, 1005);
+    TEST_ASSERT_NOT_NULL(q.current(1000));
+    TEST_ASSERT_EQUAL_STRING("late", q.current(1000)->text.c_str());
+}
+
+void test_burst_shows_each_toast_in_turn() {
+    ToastQueue q(3000);
+    for (int i = 1; i <= 3; i++) q.push(std::to_string(i), NotificationLevel::Info, 1002);
+    TEST_ASSERT_EQUAL_STRING("1", q.current(1000)->text.c_str());
+    TEST_ASSERT_EQUAL_STRING("2", q.current(4002)->text.c_str());
+    TEST_ASSERT_EQUAL_STRING("3", q.current(7002)->text.c_str());
+    TEST_ASSERT_NULL(q.current(10002));
+}
+
+void test_each_toast_has_its_own_id() {
+    ToastQueue q(3000);
+    q.push("a", NotificationLevel::Info, 0);
+    q.push("a", NotificationLevel::Info, 0);  // same text, still a different Toast
+    uint32_t first = q.current(0)->id;
+    TEST_ASSERT_NOT_EQUAL(first, q.current(3000)->id);
+}
+
 int main() {
     UNITY_BEGIN();
     RUN_TEST(test_nothing_shown_when_empty);
@@ -73,5 +101,8 @@ int main() {
     RUN_TEST(test_flood_keeps_the_visible_toast_and_drops_the_oldest_waiting);
     RUN_TEST(test_dismiss_shows_the_next_one_immediately);
     RUN_TEST(test_reports_when_a_new_toast_appears);
+    RUN_TEST(test_asking_with_a_slightly_older_time_does_not_expire_the_toast);
+    RUN_TEST(test_burst_shows_each_toast_in_turn);
+    RUN_TEST(test_each_toast_has_its_own_id);
     return UNITY_END();
 }